From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935081AbXEIGXe (ORCPT ); Wed, 9 May 2007 02:23:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934666AbXEIGX0 (ORCPT ); Wed, 9 May 2007 02:23:26 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:44454 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S934664AbXEIGX0 (ORCPT ); Wed, 9 May 2007 02:23:26 -0400 Date: Tue, 08 May 2007 23:23:26 -0700 (PDT) Message-Id: <20070508.232326.44096869.davem@davemloft.net> To: efault@gmx.de Cc: linux-kernel@vger.kernel.org Subject: Re: multi-second freezes with current GIT? From: David Miller In-Reply-To: <1178681360.7487.59.camel@Homer.simpson.net> References: <20070508.184458.21594839.davem@davemloft.net> <1178681360.7487.59.camel@Homer.simpson.net> X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Galbraith Date: Wed, 09 May 2007 05:29:20 +0200 > On Tue, 2007-05-08 at 18:44 -0700, David Miller wrote: > > I've been noticing this off and on for the past week or so. > > > > The system seems to jam up for several seconds, anything that would > > need to read from disk just sits there during this time. I think it's > > correlated with generating a lot of dirty write data. > > > > My mouse moves around in X etc. so it really is only processes that > > need to read from disk that get stuck. > > > > Perhaps it's a side effect of those dirty ratio changes Linus made to > > start off the 2.6.22 merge cycle? > > Uhoh, that seems highly likely. > > I think those changes may have been triggered by my repeatable and truly > horrible system stalls when writing to an ext3 data=ordered nearly full > filesystem. Anything that does fdatasync() and/or fsync() can cause > very bad experiences indeed. KDE's little menu/program launcher > doohickey does fdatasync() for some odd reason, which has utterly killed > my entire GUI for up to and including 20 minutes at a whack. > > Switching to data=writeback cured those horrors. Lowering the dirty > ratio reduced the agony of data=ordered tremendously, but didn't make it > even remotely acceptable. I'm using data=ordered on my partitions too.